Data storage systems commonly employ block-based replication solutions for protecting the data they store. Conventional block-based replication solutions operate on storage volumes (e.g., Logical Unit Numbers, or “LUNs”) using Fibre Channel or iSCSI (Internet Small Computer System Interface).
A well-known example of a block-based replication solution is the RecoverPoint system available from EMC Corporation of Hopkinton, Mass. RecoverPoint systems include a replication splitter realized in software, e.g., on a storage processor (SP) that accesses a local block-based array, one or more local replication appliances, and one or more remote replication appliances connected to a remote array configured as a replica site. The replication appliances connect to data storage systems and other replication appliances over a network, and multiple replication appliances can be configured in clusters for load sharing and increased throughput. As a data storage system receives IO requests specifying data to be written to a particular LUN on the local block-based array, the replication splitter intercepts the IO request and sends it to the local replication appliance (or appliances), e.g., over a Fibre Channel or iSCSI connection. The local appliance communicates with the remote appliance, e.g., over a WAN (Wide Area Network), and manages the storage of the data specified in the IO request at the replica site. In this manner, the replica site is made to store data that provide a redundant copy of data on the LUN, which may be used to recover the contents of the LUN in the event of a failure on the local array.
Some data storage systems employ file-based replication. A well-known example of a file-based replication solution is the Celerra Replicator™ V2, also available from EMC Corporation of Hopkinton, Mass. File-based replication typically operates by taking snaps (e.g., point in time copies) of files and file systems at a local site, comparing current snaps with previous snaps, and sending differences to a destination site. The destination site accumulates and stores the differences, which it can use to reconstitute the file or file system being replicated in the event of a failure at the local site.